Growth of the average multiplicity of particles in high-energy collisions.

The data on the growth of the average charged-hadron multiplicity in p (pBAR)-p collisions from square-root s = 5 to 900 GeV, and in e+e- annihilation from 10 to 90 GeV, are described by the same slowly increasing power of s. The power approaches an asymptotic value of the order of 0.1 only at square-root s approximately 1000 TeV. The ratio of the average multiplicity in e+e- annihilation to that in pp collisions is nearly constant at 1.5; thus, the difference between these averages increases. A small but increasing energy fraction tends to be removed from particle production in the extreme fragmentation region; this sustains relatively increasing production of high multiplicities of soft particles.